Switch with arc-suppressing device



P 1954 P. M. CHRISTENSEN SWITCH wrm ARC-SUPPRESSING DEVICE 2 SheetsSheet 1 Filed Feb. 10. 1949 INVENTOR. PAULM. CHRISTENSEN ATTORNEYS p 1954 P. M. CHRISTENSEN 2,689,291

swrrcu WITH ARC-SUPPRESSING DEVICE Filed Feb. 10, 1949 2 Sheets-Sheet 2 1 3 C s 7 M F 3 A 1 P y 69mm,

ATTORNEYS Patented Sept. 14, 1954 SWITCH WITH ARC-SUPPRESSING DEVICE Paul M. Christensen, West Orange, N. J assignor to Federal Electric Products Company, Newark,

N. J a corporation Application February 10, 1949, Serial No. 75,637

8 Claims.

This invention relates to an electric switch and to are interrupting devices therefor.

One object of the present invention is to provide an electric switch with an arc chamber or hood of improved construction and arc-confining and interrupting operation.

A further object of the invention is to provide an arc interrupting device which, upon installation, is automatically aligned with the switch contact members.

Another object of the invention is to provide an arc interrupting device which is not subject to lateral, vertical or rotary displacement by the switch contact members.

Another object of the invention is to provide an arc interrupting device including a hood or arc-muffle chamber and are barrier means which prevents or greatly impedes the passage of the are through the hood opening through which the movable contact member passes during the opening of the switch.

Another object of the invention is to provide an arc interrupting device having arc-barrier members which are movable during the interruption of the switch in such a manner that the axes of said barrier members move laterally in a transverse plane beyond the plane of the outer surface of the walls of said device, thereby permitting its use with a multi-element type of switch contact member having greater relative thickness than the usual type of contact member.

The above and other objects, features and advantages of the invention will be more fully understood from the following description considered in connection with the accompanying illustrative drawings which show preferred embodiments of the arc interrupting device of this invention.

In the drawings:

Fig. 1 is a side view of a switch with the arc interrupting device of the present invention, the switch being in open or circuit interrupting position;

Fig. 2 is a plan view'of the switch and are interrupting device shown in Fig. 1;

Fig. 3 is a front end view of the arc interrupting device; 7

'Fig. 4 is a sectional view on the line 4-4 of Fig 3;

Fig. 5 is a sectional view on the line 5-5 of Fig. 1;

Fig. 6 is a side view of the switch in closed or circuit making condition, with the arc interrupting device removed;

Fig. 7 is a plan view of the switch shown in 1'18- 6;

Fig. 8 is a sectional view taken along the line 8-8 in Fig. 7

Fig. 9 is a side view of a modification of the arc interrupting device;

Fig. 10 is a rear end view of the modification shown in Fig. 8; and

Fig. 11 is a sectional view taken along the line lI--Il of Fig. 10.

In the drawings, the arc interrupting device of the present invention is illustrated as applied to one pole of a switch, but it will be understood that said are interrupting device can be utilized in a switch having any number of poles. Also, in the switch illustrated, the switch actuating member is positioned below the movable contact member for moving it into and out of engagement with the stationary contact member. However, it will be understood that any other type of switch actuating member can be used with the movable contact and are interrupting device of the present invention. Although the invention is applicable to various types of switches, it is intended primarily for use in a switch operated by a quick make and break actuating mechanism.

Referring now to the drawings in greater detail, the switch, which is shown here as provided with the movable contact member and are interrupting device of the present invention, comprises an insulation panel or base 20 provided with a longitudinal groove 2|. Movable contact member 30 and stationary contact member 10 and the switch terminals (only one of which, 12, is here shown) are mounted on base 20.

Movable contact member 30 is formed by blades 3| and 32. Each blade is formed from a flat strip of material which has good electrical conducting properties and is recessed at its center, as shown at 29 in Figs. 2 and '7. The recessed portions 29 are placed back to back to form the bifurcated blade portions 46 and 41. The sides of each blade, in the bifurcated portion 46, beginning from a point approximately midway between the fork 48 and ends 33 and 34, are bent upwardly to form outward flares at the top and bottom of the passageway between the blades, as

shown in Fig. 2, which passageway extends up to fork 48. This permits the ready entrance of stationary contact member 10 between the blades. Insulation members 22 are positioned in recesses 29 and are provided with dependent hooked portions for engagement with actuating member 21. The dependent portions are shaped to fit within groove 2| in base 20 when the switch contact members are engaged and. serve to stop the downward movement of movable contact member 30 when they are moved into position in the groove.

It will be understood that insulation members 22 may be of different shapes and different forms and be otherwise positioned for engagement with other types of switch actuating members. Flat p ings 38 and 39 are positioned against the outer side of each portion of insulation member 22 disposed within recesses 29 and are secured to movable contact member 30 by rivets 31, or other suitable means, which pass through aligned openings in flat springs 38 and 39, insulation members 22 and blades 3| and 32. Flat springs 33 and 39 press the end portions 33 and 34 of the blades toward each other and against stationary contact member 10 to make and maintain good electrical contact with said stationary contact member. To aid in accomplishing this result, the flat springs are provided with upturned end portions 44 and 45 as shown in Figs. 2 and 7. Spring portions 44 and 45 apply a converging pressure against end portions 33 and 34 and fit between the upwardly bent sides in said end portions, as shown in Fig. 2. The inner end portions 49 of the fiat springs press against the outer ends of the bifurcated portion 41 formed by blades 3| and 32. The hinge contact or lug 23, to which movable contact member 30 is pivotally secured, as will hereinafter be set forth, is attached to insulation panel 29 by means of screws 24. Lug 23 is provided with parts 25 and 26 engageable with the terminal of a fuse (not shown). Movable contact member 39 is pivotally mounted on lug 23 by the flat head pin 4| which passes through aligned openings in flat springs 38, 39, blades 3|, 32 and lug 23, as shown in Fig. 8. Pin 4| is provided with a circular groove 42 and adjacent ball end 43. Slot 40 is provided at each end of fiat springs 38 and 39 adjacent the pivoted end of movable contact 30. When pin 4| is inserted through contact member 30 and lug 23, a portion of spring 38 around the aligned opening through slot 49 presses into groove 42, as shown in Fig. 8. In this manner, pin 4| is held in operative position by spring 38 but can readily be withdrawn when it is desired to remove contact member 30 for repair, replacement or cleaning purposes. Springs 38 and 39 by applying pressure to the ends of the bifurcated portion 41 assure and maintain good electrical contact with lug 23.

Stationary contact member 10 is mounted on insulated base 20 by screw H and is provided with switch terminal 12. Stationary contact member ID is disposed to fit, under the resilient pressure of springs 38 and 39, between the sides of the bifurcated portion 46 formed by blades r 3| and 32 of movable contact member 30 and to make good electrical contact therewith. In this connection, it will be understood that when the movable contact member 30 engages contact 10, the latter flexes the sides of portion 46 laterally away from each against the pressure of said springs, so that contact member 10 is firmly engaged between said sides of the movable contact member.

The are interrupting device 50 comprises a chamber or arc-muflle hood having a pair of laterally spaced side walls a rear end wall 52 and a lower front spacing portion 53. A slot 54 is provided in the lower front portion 53 to receive stationary contact member 19, as shown in Fig. 5, whereby to assure proper alignment of arc interrupting device '50 relative to movable contact member 30 and stationary contact member and to prevent, during movement of the switch, lateral displacement of the device.

4 A cut-out portion 55 in the rear end wall 52 is provided with an aperture 55 through which a screw 51, or any other suitable device, fastens the arc interrupting device to base 20. In this manner the device is firmly secured against rotary displacement and also against upward and rearward displacement when the switch contacts are disengaged, while being readily removable for inspection, repair or replacement. One or more vents 5B are preferably although not necessarily, provided in the rear wall 52 of the hood. As will be apparent from Figs. 3 and 4, the abutting wall portions at the bottoms of the side walls 5|, provide a mounting base for the device 50 which serves to close the device at the bottom thereof. Said mounting base is provided with the previously mentioned slot 54 to hold the device against lateral displacement and to facilitate the mounting of the device in position. as in Fig. 1, wherein it straddles the contact 10.

The hood may be fabricated from any suitable insulating and heat resisting material and. to facilitate molding, said hood is preferably formed in two separate halves which are joined together by rivets 59, or any other uitable means. When are interrupting device 50 is mounted in position on base 20, stationary contact member ID is d sposed within slot 54 and extends upwardly into the chamber between side walls 5|. The movable contact member 39 is movable into and out of the chamber within device 50 through the passage constituted by the upper end opening 13 and the front opening I4 of the chamber.

The arc-muffle hood is provided with arc'barrier means constituted by a pair of cylindrical members and 6| which are mounted in companion openings 52 formed in side walls 5|. Said cylindrical members 60 and GI fit with a slight clearance in their companionwall openings 62, as shown in Fig. 1 and Fig. 4, so that they can move forward and away from each other and can also rotate in their companion wall open ing about their longitudinal axes. Arc barrier members 60 and GI are formed of any suitable insulating material. It will be noted that members 59 and 6| are positioned between the companion contact members, in the open condition of the switch, and are in the path of movable contact member 30. Said members 60 and 6| are movable toward and away from each other transversely of the passage through which the movable contact member 30 moves for engaging and disengaging the companion stationary con tact member ID. Members .60 and 6| are freely rotatable on pins or carriers 66, which extend through cylinder bores '16 in said members. and are rotatably positioned in grooves 55 in side walls 5|. Each wall 5| is provided, on its outer surface, with pairs of outwardly projecting portions 53 extending from groove 95. The projections 53 form guides for said pins .86 in the movement of members 60 and BI laterally of side walls.

5| during the opening and closing of the switch. Each member 60, 3| is free to rotate on its pin 69. When inserted in members 69, 9|, each pi projects laterally on each side of its companion member 60, 6|, as shown in Fig. l. Adjac nt each of its ends, each pin 66 is provided with a peripheral groove 61. The grooved portion o each pin 35, is disposed in an outer end portion of each side wall groove 65. A U-shaped wire spring 69 is affixed to the outer surface of side wall 5| by a rivet 69, or any other suitable means. The free ends of each spring 58 are resiliently disposed within the two peripheral grooves .61 on ach pin 66, Springs 68 bias pins 66 into the grooves 65, and normally maintain barrier members 60, 6| in abutting relation or contact with each other. Barrier members 60, 8| upon the passage of movable contact member 30 through the arc chamber, are laterally displaceable in guides 63 against the inward bias of springs 68 and are free to rotate about their axes while pins 66 are positioned in grooves 65 or guides 63.

As shown in Fig. 1, device 50 is positioned so that it is forwardly inclined. In this position barrier members 60, BI are disposed above stationary contact 18. As here shown, the members 68, 8| are parallel to the forwardly inclined top edge 75 of contact 10. By reason of this position and arrangement of members 88, 6], any are which forms between the inclined top surface of member 10 and the confronting edge portions of movable contact member 30 strikes adjacent surface portions of said members 60, 6| and is subjected to the cooling action of the latter. Further, it will be observed that in the movement of the movable contact member 38 from its position in which it engages the companion stationary contact member 10 to a position out of engagement therewith, said movable contact member must pass between barrier members El, 62 at which time the latter are held in resilient engagement with the opposite sidesof said movable contact by springs 68 which, however, permit said members til, 62 to move away from each other along channels 64, against the action of said springs to make room therebetween for said movable contact member. Thus, the movable contact member 30 engages said members 68, 6| during the openin of the switch and causes said members to rotate freely about their longitudinal axes, thus presenting progressively diiferent and cool surface portions thereof to the arc. In addition, as contact member 30 is being moved out of engagement with stationary contact iii, insulation member 22 projects into the arc chamber and acts as a barrier to the passage of the are through the front opening of the chamber.

Another embodiment 88 of my arc interrupting device is shown in Figs, 9, 10 and 11. In this embodiment, the arc chamber or hood is defined by a pair of laterally spaced opposite side walls 8|, a rear end wall 82 and a lower front portion 89, all of insulation material. In the same manner as device 50, the present embodiment has a rear cut-out portion 83 provided with an aperture 85 through which a screw, or other suitable means, is inserted to hold the device 88 in position and to prevent its rotary and vertical displacement. Device 88 is readily removable from the switch for inspection or replacement, by the removal of the screw in aperture 85. Similarly, device 80 is provided with a slot 88 in lower front portion 89. When affixed to the switch, stationary member 10 is disposed within slot 88 to establish the proper alignment of device 80 relative to the switch contact members. Moreover, with stationary member 1:) disposed snugly in slot 88, lateral displacement of device 80 is prevented. As in device 5:), device 80 is preferably, although not necessarily, provided with vents 8B in rear end wall 82, which serve the same function. Device 89 is preferably formed in two parts, for convenience in molding.

If formed of two sections, they would be provided with aligned apertures to receive rivets 84, or any other suitable fastening means, in order to join the separate sections. The inner surface of each wall BI is corrugated to define alternate rounded ridges 81 and furrows 90. By reason of the corrugated formation of the inner surfaces of walls 8!, the arc chamber in device is effectively provided with increased internal surface area to improve the arc-cooling action.

When the switch contacts are engaged depending member 22 is positioned in front of the hood. As switch member 30 is moved out of. engagement with contact It, insulation member 22 projects into the hood and acts as a barrier to the passage of the are through the front opening of the hood.

Thus, it is seen that the arc interrupting and switch construction described above is well adapted to accomplish the objects of the invention. It will be understood, however, that the latter may be embodied otherwise than as herein disclosed and that certain changes in details of construction and in arrangement of the parts might be made without departing from the underlying idea or principles of this invention. Also, the arc interrupting devices of the present invention can be associated with a single pole switch, as illustrated, as well as with a switch having a plurality of poles and it will be understood further that this invention can be applied to switches of types which differ from that of the illustrated switch.

Certain matter disclosed but not now claimed herein is claimed in my divisional application, Ser. No. 137,401, filed January 7, 1950, now Patent No. 2,596,983, dated May 20, 1952.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. An are muffler hood for an electric switch, comprising a pair of laterally spaced side walls provided with openings therein, cylindrical arc-- barrier members mounted in said openings for movement toward and away from each other, and pin members carrying said arc-barrier members for said movement of the latter and for rotation about the axes of said pin members, respectively, said side walls having parts in which said pin members are mounted for movement relative to said side walls, respectively.

2. An arc mufiler hood comprising a pair of laterally spaced walls provided with openings therein, said walls having grooves in their outer surfaces on each side of said openings, and a cylindrical arc-barrier member mounted in each of said openings, said barrier member being provided with a pin member axially thereof, said pin member being positioned in said grooves for rotation therein.

3. An arc interrupting device for an electric switch provided with mounting means and having companion relatively movable contact members, said device comprising a pair of laterally spaced walls between which one of said contact members is positioned and between which the other switch contact member is movable for engagement with and disengagement from the companion contact member, the inher surfaces of said walls being grooved to provide an enlarged arc cooling surface, a third wall disposed between said pair of spaced walls at the rear ends thereof, said third wall having a plurality of passageways therethrough for venting said device, a lower portion joining said walls and providing a bottom closure for said device, said portion defining a slot toward the front of saiclportion intermediate said walls and defining a longitudinal aperture extending through said lower portion rearwardly of said slot, a portion of said one contact member being disposed within said slot whereby said device is aligned for the engagement of said contact meme bers and secured against lateral displacement during engagement and disengagement of said members, and means for mounting said device on said switch mounting means through said aperture whereby said device is retained against vertical and lateral displacement during said engagement and disengagement.

4. An arc interrupting device for an electric switch having companion relatively movable contact members, said device comprising a pair of laterally spaced walls between which one of said contact members is positioned and between which the other switch contact member is movable for engagement with and disengagement from the companion contact member, arc-barrier members mounted in said walls, respectively, for movement therein transversely of the space therebetween in the path of said other switch contact, from a first position in which said arc-barrier members are in engagement with each other to a second position in which said arc-barrier members are in laterally spaced relation allowing movement of said other contact member into and out of engagement with said companion contact member, each of said arc-barrier members being provided on a carrier, projecting means on said walls movably mounting 'said carriers, respectively, for simultaneously directing in one transverse plane said movement of each of said arc-barrier members, and resilient means for releasably holding said arc-barrier members in said first position.

5. An arc interrupting device for an electric switch having companion relatively movable contact members, said device comprising a pair of laterally spaced walls between which one of said contact members is positioned and between which the other switch contact member is movable for engagement with and disengagement from the companion contact member, arc-barrier members mounted in said walls, respectively, for movement therein transversely of the space therebetween in the path of said other switch contact, from a first position in which said arc-barrier members in engagement with each other to a second position in which said arc-barrier members are in laterally spaced relation allowing movement of said other contact member into and out of engagement with said companion contact member, each of said arcbarrier members being provided on a carrier, means on said walls for simultaneously directing in one transverse plane said movement of each of said arc-barrier members, said means comprising guides extending from the outer surface 01 each of said walls and movably mounting said carriers, respectively, for the movement of each of said arc-barrier members outwardly of said walls, and resilient means for biasing said arc-barrier members for movement toward each other.

6. In an arc interrupting device for an electric switch having companion relatively movable contact members, said device comprising a pair of laterally spaced walls between which one of said contact members is positioned and between which the other switch contact member is movable for engagement with and disengagement from the companion member, and a pair of arc barrier members mounted within openings in said walls and movable by said other switch contact member as it moves for engagement with and disengagement from said positioned member; means for directing and guiding the movement of said barrier members in a plane transverse said walls comprising proiections formed on the outer side of each of said walls, and means carried centrally of each of said barrier members, said latter means being mounted for move ment in said guide means, whereby said latter means are movable relative to said walls, respectively.

'7. In an arc interrupting device for an electric switch having companion relatively movable contact members, said device comprising a pair of laterally spaced walls between which one of said contact members is positioned and between which the other switch contact member is movable for engagement with and disengagement from the companion member, and a pair of arc barrier members mounted within openings in said walls and movable by said other switch contact member asit moves for engagement with and disengagement from said positioned member; means for directing and guiding the movement of said barrier members comprising projections on the outer side of each of said walls on each side or the opening therein, each arc barrier member being positioned between the projections on each wall and being provided with pin members mounted for movement in said projections, and resilient means engageable with said pin members for biasing said barrier members for movement toward each other.

8. An arc interrupting device for an electric switch having companion relatively movable contact members, said device comprising a pair of laterally spaced walls between which one 01' said contact members is positioned and between which the other switch contact member is movable for engagement with and disengagement from the companion contact member, said walls having openings defined therein and being provided with grooves in their outer surfaces on each side of said openings, and a cylindrical arcbarrier member mounted in each of said openings, said barrier member being provided with a pin member axially thereof, said pin member being positioned in said grooves for rotation therein, said one contact member having a forwardly inclined top edge, and said pin members being parallel to said top edge whereby said arc-barrier members are in parallel relationship to said top edge.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 883,389 Clay Mar. 31, 1908 983,660 Van Nuis Feb. '7, 1911 1,554,528 Sachs Sept. 22, 1925 1,851,248 Hammerly Mar. 29, 1932 1,922,060 Sachs Aug. 15, 1933 2,098,578 Hammerly Nov. 9, 1937 2,323,476 Lantz July 6, 1943 2,393,385 Landmeier Jan. 22, 1946 2,399,449 Prussack Apr. 30, 1946 FOREIGN PATENTS Number Country Date 228,591 Great Britain Feb. 4, .1925 

